August 26, 2008 / 5:00 PM / 9 years ago

New flu vaccine approach hopeful, Novavax says

WASHINGTON (Reuters) - A new type of bird flu vaccine that uses a mock version of the virus appears to protect people against infection and is safe enough to continue testing, Novavax Inc. said on Tuesday.

The Rockville, Maryland-based biotech company released the first results of human safety trials of its experimental vaccine against H5N1 avian influenza and said it appeared to work as well as other vaccines.

"These results are strong and very competitive and they compare well with any vaccine against pandemic flu, whether licensed or in development," Novavax President and Chief Executive Officer Dr. Rahul Singhvi told investors in a conference call.

Most influenza vaccines use either a weakened but live flu virus or a killed virus to stimulate the immune system. They must be reformulated every year to match the constantly mutating flu strains and take months to make using specially grown live chicken eggs.

Novavax grows the vaccine in lab dishes of caterpillar cells in a process the company believes will be quicker than current technology and uses a decoy of the virus called a virus-like particle. "It looks like the virus in that it has the same size and shape as the virus," Singhvi said.

But it lacks the genes needed to replicate itself. "It is not a virus but the body views it as a virus," he said.

No one knows when the next influenza pandemic will strike but experts are now very worried about the H5N1 avian influenza virus sweeping through poultry in Asia, Europe, the Middle East and Africa. It rarely infects humans now but has killed 243 out of 385 infected since 2003 and could mutate into a more infectious form.

PROTEIN TARGETS

Several companies and other groups are working to make a vaccine that would protect against H5N1.

Most licensed vaccines focus on hemagglutinin -- a protein that gives flu viruses the "H" in their names. The Novavax vaccine stresses three proteins found in flu viruses -- the H, the neuraminidase or "N" protein and the M1 protein, which scientists believe may change less from one flu strain to another.

The highest dose of the vaccine stimulated the development of a protective level of antibodies in 94 percent of those vaccinated, the company said.

"Two doses of this novel vaccine -- which is designed to prevent bird flu -- gave strong immune responses. The data are encouraging that this new vaccine approach can help prevent pandemic influenza," Dr. Robert Belshe of the Saint Louis University School of Medicine in Missouri, who served on the Data and Safety Monitoring Board for the study, said in a statement.

"We will proceed with clinical development when we have a partner," Novavax's chief medical officer Dr. Penny Heaton told the call. The company, which will start testing a seasonal flu vaccine later in the year, said it would submit its findings to the peer-review system of medical journals and meetings.

The GE Healthcare unit of General Electric Co collaborates with Novavax to supply plastic disposable bio-reactors for use in making the vaccine, an innovation the companies believe is more efficient than using steel tanks and filtration systems that must be cleaned and revalidated each time they are used to make different batches.

Editing by Julie Steenhuysen and Vicki Allen

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